Instruction Types; Arithmetic Instructions - IBM 1620 1 Manual

Instruction Types
All 1620 instructions fall into six general categories
according to function:
1. Arithmetic
2. Compare
3. Branch
4. Internal Data Transmission
5. Input/Output
6. Program Control
The Divide and Floating-Point instructions are 1620
Model 1 special features and must be ordered as such
for inclusion in the 1620 Model 1 repertoire of in-
structions-Move Flag, Transfer Numerical Fill, and
Transfer Numerical Strip.
Table 1.
1620 Instructions
12
I nstruct ions
Arithmetic
Add
Add (1)
Subtract
Subtract
(1)
Multiply
Multiply (I)
Load Dividend*
Load Dividend (1)*
Divide*
Divide (1)*
Floating Add*
Floating Subtract*
Floating Multiply*
Floating Divide*
Compare
Compare
Compare (I)
Branch
Branch
Branch No Flag
Branch No Record Mark
Branch No Group Mark *
Branch on Digit
Bronch Indicator
Branch No Indicator
Branch and Transmit
Branch and Transmit (I)
Branch Back
Branch and Transmit
Floating*
* Speci a I Feature
(I) Immediate
Mnemonic
A
AM
S
SM
M
MM
LD
LDM
0
OM
FADD
FSUB
FMUL
FDIV
C
CM
B
BNF
BNR
BNG
BD
BI
BNI
BT
BTM
BB
BTFL
Code P&Q P
21 X
11 X
22
X
12
X
23
X
13
X
28
X
18
X
29 X
19
X
01
X
02
X
03 X
09 X
24 X
14
X
49
X
44
X
45
X
55
X
43 X
46
X
47
X
27
X
17
X
42
07
X
All 1620 instructions with their associated Op codes,
mnemonics, modifier' digits, and allowable indirect
addresses are shown in Table 1. Modifier digits are
those required in
Qs, QI), and Qll to differentiate be-
tween instructions having the same Op codes.
Arithmetic Instructions
Data flow, field length definition, indicator control,
and sign analysis are common to all 1620 Arithmetic
instructions, and are therefore explained before the
actual instructions.
Instructions
Mnemonic Code
P&Q
P
Internal Data
Transmission
Transmit Digit
TO 25
X
Transmit Digit (I)
TOM 15
X
Transmit Field
TF 26
X
Transmit Field (I) TFM 16
X
Transmit Record TR 31
X
Transfer Numerical Strip* TNS
72 X
Transfer Numerical Fill* TNF 73
X
Floating Shift Right* FSR 08
X
Floating Shift Left* FSL 05
X
Transmit Floating* TFL
06
X
Input/Output
Read Numerically RN 36
X
Write Numerically WN 38
X
Dump Numerically ON 35
X
Read Alphamerically RA 37
X
Write Alphamerically WA 39
X
Seek* K
34 X
Program
Control
Control
K
34
Set Flag SF 32
X
Clear Flag CF 33
X
Mave Flag* MF 71
X
Halt H 48
No Operation NOP 41